what is space?

Question

how do we know its not just a big flat surface that displays 3d images of stars and planets and what-not? the images that scientists give us in tv and internet, people just automatically believe that theyre showing us reality. how much evidence is there really that stars are balls of burning gas and that its not just an image?
by the way, i noticed that yahoo answerers usually get overemotional when answering, and start criticizing like communists whenever someone asks a question. if you cant control your emotions, go to a doctor, dont bother answering.

Answer 1

In philosophy
Main article: Philosophy of space and time
Space has a range of definitions:

One view of space is that it is part of the fundamental structure of the universe, a set of dimensions in which objects are separated and located, have size and shape, and through which they can move.
A contrasting view is that space is part of a fundamental abstract mathematical conceptual framework (together with time and number) within which we compare and quantify the distance between objects, their sizes, their shapes, and their speeds. In this view, space does not refer to any kind of entity that is a "container" that objects "move through"..
These opposing views are relevant also to definitions of time. Space is typically described as having three dimensions, and that three numbers are needed to specify the size of any object and/or its location with respect to another location. Modern physics does not treat space and time as independent dimensions, but treats both as features of space-time – a conception that challenges intuitive notions of distance and time.

An issue of philosophical debate is whether space is an ontological entity itself, or simply a conceptual framework we need to think (and talk) about the world. Another way to frame this is to ask, "Can space itself be measured, or is space part of the measurement system?" The same debate applies also to time, and an important formulation in both areas was given by Immanuel Kant.

In his Critique of Pure Reason, Kant described space as an a priori intuition that (together with another a priori intuition, time) allows us to comprehend sense experience. With Kant, neither space nor time are conceived as substances, but rather both are elements of a systematic framework we use to structure our experience. Spatial measurements are used to quantify how far apart objects are, and temporal measurements are used to quantify how far apart events occur.

Schopenhauer, in the preface to his On the Will in Nature, stated that "space is the condition of the possibility of juxtaposition." This is in accordance with Kant's understanding of space as a form in the mind of an observing subject.

Similar philosophical questions concerning space include: Is space absolute or purely relational? Does space have one correct geometry, or is the geometry of space just a convention? Historical positions in these debates have been taken by Isaac Newton (space is absolute), Gottfried Leibniz (space is relational), and Henri Poincaré (spatial geometry is a convention). Two important thought-experiments connected with these questions are: Newton's bucket argument and Poincaré's sphere-world.


[edit] In mathematics
Space is a set, with some particular properties and usually some additional structure. It is not a formally defined concept as such, but a generic name for a number of similar concepts, most of which generalize some abstract properties of the physical concept of space.

In particular, a vector space and specifically a Euclidean space can be seen as generalizations of the concept of a Euclidean coordinate system. Important varieties of vector spaces with more imposed structure include Banach space and Hilbert space. Distance measurement is abstracted as the concept of metric space and volume measurement leads to the concept of measure space.

As far as the concept of dimension is defined, although three-dimensional space is the most commonly thought of dimensional space, the number of dimensions for a space to exist need not be three: it can also be zero (a point), one (a line), two (a plane), more than three, finite or infinite, and with some definitions, a non-integer value. Mathematicians often study general structures that hold regardless of the number of dimensions

In physics
Space is one of the few fundamental quantities in physics, meaning that it cannot be defined via other quantities because there is nothing more fundamental known at present. Thus, similar to the definition of other fundamental quantities (like time and mass), space is defined via measurement. Currently, the standard space interval, called a standard meter or simply meter, is defined as the distance traveled by light in a vacuum during a time interval of 1/299792458 of a second (exact). This definition coupled with present definition of time makes our space-time to be Minkowski space and makes special relativity theory to be absolutely correct by definition.

In classical physics, space is a three-dimensional Euclidean space where any position can be described using three coordinates. Special and general relativity uses space-time rather than space; space-time is modeled as a four-dimensional space (with the time axis being imaginary in special relativity and real in general relativity, and currently there are many theories which use more than four-dimensional spaces (both real and complex).

Before Einstein's work on relativistic physics, time and space were viewed as independent dimensions. Einstein's discoveries have shown that due to relativity of motion our space and time can be mathematically combined into one symmetric object — space-time. (Distances in space or in time separately are not invariant versus Lorentz coordinate transformations, but distances in Minkowski space-time are — which justifies the name).

Answer 2

"...how much evidence is there really that stars are balls of burning gas and that its not just an image?..."

1. Investigate for yourself something called spectroscopy. It's an established scientific research technique that reveals what elements are present in an energized mass of gas or plasma. Spectroscopy done on stars is consistent with any mass of heated gas or plasma.

2. Our sun is a star. It generates heat and light, ergo other stars do too.

3. If the sun isn't evidence enough that stars are as advertised by astrophysicists, then what else could the sun and other stars be????

"...what is space?..."
Any given volume without any thing in it.

Answer 3

Since space flight has now become commercialized, where are they flying them if not to what we hold as 'space'? Their statements agree with governments and scientists, so on what grounds should we doubt them? I understand and respect those that question what they hear, but there comes a point where you have to accept the overwhelming evidence that supports a belief opposite yours.

Edit: What does this question have to do with communism?

Answer 4

Space refers collectively to the relatively empty parts of the universe. Any area outside the atmospheres of any celestial body can be considered 'space'. Although space is certainly spacious, it is not always empty, but can be filled with matter — say a tenuous plasma. In particular, the boundary between space and Earth's atmosphere is conventionally set at the Karman line.

Answer 5

There is plenty of evidence indicating the nature of stars. For instance, there are several different methods for determining distance and it is apparent that there are galaxies in all directions spanning billions of light-years,

Also, with spectroscopy, we can tell of what they are constituted.

Answer 6

space is an airless environment where no human lif form can survive or we just plainly call space VACUUM